The first four series of the BBC drama adapted from Jennifer Worth's memoirs about a group of midwives working in poverty-stricken East London in the 1950s and '60s.
Jenny Lee (Jessica Raine) gets her first job at Nonnatus House which she soon realises is a nursing convent and not a hospital, as she had assumed.
As she begins caring for patients, she gradually becomes accustomed to her new environment, making friends with fellow midwives Cynthia (Bryony Hannah), Trixie (Helen George) and the clumsy Chummy (Miranda Hart).
In series two, it's 1958, and while Jenny has her hands full dealing with an abused patient, Trixie and Sister Evangelina (Pam Ferris) are forced to board a Swedish cargo ship to tend to the captain's pregnant daughter.
In series three, set in 1959, the midwives temporarily find themselves without a place to work when an unexploded bomb is found near Nonnatus House.
Meanwhile, Sister Winifred (Victoria Yeates) attempts to settle in to life at Nonnatus and Chummy arranges for Princess Margaret to visit to raise awareness of their weekly clinics.
In series four, the midwives are joined by new recruit Barbara Gilbert (Charlotte Ritchie), but she doesn't get off to the best of starts after a night out with Trixie and Patsy (Emerald Fennell).
Meanwhile, Barbara has to aid a first-time mother when her birth doesn't go according to plan and Sister Julienne (Jenny Agutter) struggles with the financial pressures on Nonnatus House.